The U.S. patent of Bonanni, U.S. Pat. No. 4,818,058, granted Apr. 4, 1989, incorporated by reference herein, is an example of the literature describing the use of monocrystalline silicon support elements for supporting an optical fiber with a sufficient degree of precision that it can be spliced with another fiber, i.e., abutted to the other fiber with sufficient precision to allow optical energy to flow unimpeded through the abutment. Such support members are made by photolithographically masking and etching matching V-grooves in two support elements. Such grooves can be made with great precision in properly oriented monocrystalline materials such as silicon because mask openings can be made photolithographically and the sidewalls of the grooves are defined by crystallographic planes. Thus, with each optical fiber contained between opposite V-grooves of matching support elements, the location of the optical fiber is precisely controlled. Typically, several parallel optical fibers are held side-by-side between two fiber support elements which constitute a connector. This array of fibers can in turn be spliced to a similar array by abutting them against the other array held by another connector.
The use of V-grooves in monocrystalline substrates to support optical fibers presupposes a uniform etch rate along the length of the substrate. Silicon etching has been used for many years in the integrated circuit art, and so it is well known that the V-grooves can be etched by appropriate masking of a wafer and immersing in a heated etchant such as ethylene diamine pyrocatechol (EDP). Economy of scale requires that numerous semiconductor wafers be etched at one time, with the wafers thereafter being cut to form individual support elements. It has been found, unfortunately, that V-grooves formed in the conventional manner are not always uniformly etched along their entire lengths. That is, some of the V-grooves may contain "bumps," regions at which the silicon has not been etched away to a sufficient depth. These bumps may prevent an optical fiber from seating firmly within the V-groove as is required for its alignment in accordance with the principles of the Bonanni patent.